Research on a New Type of Neutral Point Grounding Protection Device for Transformers

Traditional transformer neutral grounding protection device, using a combination of discharge gap and lightning arrester, discharge gap rod pole exists easy to trigger flashover along the surface, low corona voltage, with inaccurate parameters, poor arc extinguishing ability, overvoltage protection dead zone, easy to cause circuit breaker error operation and other defects. In this paper, for the above problems, a new transformer neutral grounding protection device is proposed, which adopts the combination device of logic control module, voltage transformer, current transformer, fast load switch and lightning arrester, and pre-set the closing and breaking voltage range of fast load switch by comparing the circuits, accurately restricts the protection range of fast load switch and lightning arrester, It effectively solves the problems of high failure rate, low sensitivity, poor accuracy and large dead zone of over-voltage protection existing in the current transformer neutral grounding protection device.